1. Technical Field
The present disclosure relates to a display control method, a display control apparatus, and a display apparatus that control display of information for alerting a driver for safe driving.
2. Description of the Related Art
Nowadays, an advanced driver assistance system (ADAS) that alerts a driver for safe driving is in increasingly widespread use. Examples of the features of ADAS application include lane departure warning (LDW), forward collision warning (FCW), and pedestrian collision warning (PCW). ADAS detects, for example, driving conditions, such as traffic lanes, other vehicles ahead and behind the vehicle, and a pedestrian present in front of the vehicle, using, for example, a vehicle-mounted camera or a radar system. Thereafter ADAS displays information based on the results of detection. The information is displayed on, for example, a meter display, a head-up display (HUD), a head-mounted display or a helmet-mounted display (HMD), or smart glasses.
The human visual field is divided into a foveal vision and a peripheral vision. In terms of the visual resolution, foveal vision constitutes about 2 degrees of our visual field (a range within a radius of about one degree from the center of the fovea) (refer to, for example, L. L. Sloan, “The photopic acuity-luminance function with special reference to parafoveal vision”, Vision Research, 1968, pp. 901-911). In terms of the retina structure, foveal vision constitutes 5 degrees of our visual field (refer to, for example, “The Vision Society of Japan Handbook of visual information processing”, Asakura Publishing Co., Ltd., 2001, pp. 237). In contrast, according to the neuroanatomy of the visual cortex, foveal vision constitutes 7 degrees of our visual field (refer to, for example, M. Mishkin, L. Ungerleider, “Contribution of striate inputs to the visuospatial functions of parieto-preoccipital cortex in monkeys”, Behav Brain Res, 1982, pp. 57-77). The foveal vision is created by a large number of cone cells and provides us with our sharpest vision, or highest acuity of vision and color discrimination ability and, thus, clear vision. In contrast, peripheral vision is created by a few cone cells and provides us with poor color perception. In addition, the visual acuity of the peripheral vision is lower than that of the foveal vision. However, the peripheral vision is created by rod cells that are of high density, and the peripheral vision is significantly sensitive to motion stimuli. The peripheral vision plays an important role in recognizing a spatial position relationship or perceiving a moving object. That is, the human eye has an ability to detect a moving object in the peripheral vision and perceive the details of the object in the foveal vision.
The difference between the visual characteristics in the two visions of the human eye may sometimes cause a traffic accident. For example, since the driver of a vehicle that is moving on a straight road pays attention to the road in front of the vehicle or a vehicle ahead, it is difficult for the driver to find a pedestrian who suddenly steps into the path of the vehicle. This is because the moving speed of the pedestrian is low and the moving distance of the pedestrian is short as compared with the driving environment including the vehicle or the road ahead to which the driver pays attention and, at this situation, the driver needs to find the pedestrian stepping into the path of the vehicle in the peripheral vision. As a result, the driver fails to find the pedestrian with a small movement in the peripheral vision although it is sensitive to the movement. Furthermore, even at an intersection with good visibility in the daytime, a driver may not find a vehicle approaching toward the driver and, thus, crossing collision sometimes occurs. If in the field of vision of a driver, the positional relationship between the driver and another vehicle entering the intersection (the viewing angle from the driver to the another vehicle) does not vary and particularly if the driver only looks straight ahead without turning their eyes to the right or the left, the driver fails to see the oncoming vehicle in time. Thus, the risk of collision increases. This is because since the other vehicle does not move in the driver's vision, the driver cannot find the other vehicle that does not move in the peripheral vision sensitive to a movement and, thus, cannot recognize that the other vehicle is approaching the driver.
As an existing technology for a driver to obtain a large amount of information without turning their eyes to an object present in the peripheral vision, a display apparatus for a vehicle that displays animation that changes in accordance with the information has been developed (refer to, for example, Japanese Unexamined Patent Application Publication No. 2011-240843).